The Effect of CacyBP/SIP on the Phosphorylation of ERK1/2 and p38 Kinases in Clear Cell Renal Cell Carcinoma

Pan-analysis reveals CACYBP to be a novel prognostic and predictive marker for multiple cancers

OBJECTIVES

Cancer has emerged as a global issue in terms of public health care and treatment. The significance of calcyclin binding protein (CACYBP) in various neoplasms suggests that it may serve as a novel biomarker for numerous types of human tumors.

METHODS

Our research investigated the differences in CACYBP expression between cancer tissues and normal tissues using a total of 18,787 samples from multiple centers. To explore the prognostic factor of CACYBP in cancers, we utilized Cox regression analysis and Kaplan-Meier curves. We also conducted Spearman's rank correlation analyses to determine the associations of CACYBP expression with the immune microenvironment, etc. Additionally, we applied gene set enrichment analysis to explore the underlying mechanisms of CACYBP in cancers. A partial validation of CacyBP expression in cancer tissues was performed through lung adenocarcinoma samples using Western blotting and paired t-test.

RESULTS

Compared to normal tissues, CACYBP exhibited high expression levels in 14 cancer types, including breast invasive carcinoma, and low expression levels in six cancers, including glioblastoma multiforme (P < 0.05). CACYBP expression was found to be significantly associated with the prognosis of 13 cancers, including adrenocortical carcinoma (P < 0.05). CACYBP demonstrated a robust ability to distinguish 15 cancers, including cholangiocarcinoma, from their control samples (area under the curve > 0.8). Furthermore, CACYBP expression was correlated with tumor mutational burden, microsatellite instability, and immune infiltration levels, indicating its potential as an exciting target for cancer treatment. CACYBP may exert its effects on several signaling pathways, including cytokine-cytokine receptor interaction, in various cancers. Compared with paired adjacent specimens, the expression level of CacyBP protein was up-regulated in lung adenocarcinoma specimens (P < 0.05), partially validating the increased expression of CACYBP in cancers.

CONCLUSIONS

CACYBP has the potential to serve as a novel prognostic and predictive marker for multiple human cancers.

Celastrol Elicits Antitumor Effects through Inducing Immunogenic Cell Death and Downregulating PD-L1 in ccRCC

BACKGROUND

Targeting immunogenic cell death (ICD) is considered a promising therapeutic strategy for cancer. However, the commonly identified ICD inducers promote the expression of programmed cell death ligand 1 (PD-L1) in tumor cells, thus aiding them to evade the recognition and killing by the immune system. Therefore, the finding of novel ICD inducers to avoid enhanced PD-L1 expression is of vital significance for cancer therapy. Celastrol (CeT), a triterpene isolated from Tripterygium wilfordii Hook. F induces various forms of cell death to exert anti-cancer effects, which may make celastrol an attractive candidate as an inducer of ICD.

METHODS

In the present study, bioinformatics analysis was combined with experimental validation to explore the underlying mechanism by which CeT induces ICD and regulates PD-L1 expression in clear cell renal cell carcinoma (ccRCC).

RESULTS

The results showed that EGFR, IKBKB, PRKCQ and MAPK1 were the crucial targets for CeT-induced ICD, and only MAPK1 was an independent prognostic factor for the overall survival (OS) of ccRCC patients. In addition, CeT triggered autophagy and up-regulated the expressions of HMGB1 and CRT to induce ICD in 786-O cells in vitro. Importantly, CeT can down-regulate PD-L1 expression through activating autophagy. At the molecular level, CeT suppressed PD-L1 via the inhibition of MAPK1 expression. Immunologically, the core target of celastrol, MAPK1, was tightly correlated with CD8+ T cells and CD4+ T cells in ccRCC.

CONCLUSION

These findings indicate that CeT not only induces ICD but also suppresses PD-L1 by down-regulating MAPK1 expression, which will provide an attractive strategy for ccRCC immunotherapy.